--- forwarded message, please reply to sender and MMD ---

Yamaha's web site advises me that _none_ of their PSR models are able to
have their master oscillators "bent" or slightly changed in frequency
so as to be tunable to some other instrument (slightly out of tune)
which cannot feasibly be altered (i.e. piano).  Of course, most models
sport 1/12 octave jumps but no finer tuning.  More expensive keyboards
do, but I'm looking for the cheapest way (MIDI compatible) to do the job.

So ...  Can you point me to those who have the schematics of PSR
Yamahas?   As an elder technician, I'm sure I could modify things to
"play in the cracks".  Thanx.

John P. Lane

 [ John, Back in the 70's (or very early 80's) I owned a Yamaha
 [ CP-30 electric piano.  It was a pre-MIDI piano and did have some
 [ capability to tweak the master oscillator slightly.  Its circuitry
 [ was essentially analog, implemented in custom ASICs.  I was able
 [ to buy an "official" service manual for that unit through the
 [ dealer.  It was not cheap ($30 back then, if memory serves me
 [ right), but it was complete and accurate.  I don't think you'd be
 [ wasting your time to visit a few dealers in your area.  Ask to
 [ see their service person, even if you have to come back when that
 [ person is in.  As a fellow technician, you will probably find
 [ that if you can actually talk to them, you'll have something in
 [ common.  Often they stock service manuals, so you might be able
 [ to look at one before ordering.    -- Jody